--- a/hgext3rd/topic/compat.py	Fri Nov 15 08:14:06 2019 -0800
+++ b/hgext3rd/topic/compat.py	Fri Nov 15 11:37:34 2019 +0700
@@ -14,17 +14,13 @@
     util,
 )
 
-getmarkers = None
 successorssets = None
 try:
     from mercurial import obsutil
-    getmarkers = getattr(obsutil, 'getmarkers', None)
     successorssets = getattr(obsutil, 'successorssets', None)
 except ImportError:
     pass
 
-if getmarkers is None:
-    getmarkers = obsolete.getmarkers
 if successorssets is None:
     successorssets = obsolete.successorssets